Who Said “I Think Therefore I Am”? The famous French philosopher and mathematician René Descartes , also known as the Father of Modern Philosophy, said the words "I think therefore I am”. Much of his work attempted to defy skepticism , a prominent ideology for the French intellectuals of the day. In addition, much of his philosophical thinking lead him to speculate about the connection between the mind and the body, which is what this quote focuses upon. Descartes: “I Think Therefore I Am” Descartes wrote this quote in part IV of his work “Discourse on Method of Rightly Conducting One’s Reason and of Seeking the Truth in the Sciences” published in 1637: But I observed that, while I was thus resolved to feign that everything was false, I who thought must of necessity be somewhat; and remarking this truth--I think, therefore I am--was so firm and so assured that all the most extravagant suppositions of the sceptics [sic] were unable to shake it. I judged that I could unhesitatingly accept it as the first principle of the philosophy I was seeking. I could feign that there was no world, I could not feign that I did not exist.

Throughout “Discourse on Method,” Descartes sets up his method of inquiry. In part IV, he then doubts everything he has said and begins by telling his audience that everything he knows is false. By denying everything, he can begin his argument free and clear of prejudice and thus prove his method of inquiry. He then builds his theory beginning with the one thing that he knows to be free of doubt, and that is thought process. Senses can lie or manipulate but to know doubt is to have thoughts and thoughts lead to existence. Rene Descartes, who was born in 1596 and died in 1650, only believed in mathematics and reason. He tried to develop the proper path to deductive reasoning, which he believed was all that stood between him and defeating skepticism. However, he also had to be very careful in his work which closely followed Copernicanism when the Church had recently condemned Galileo for that very belief. Through all of his work and writings, Descartes became one of the most influential philosophers in history. "I Think, Therefore I am" Confused: What does this Phrase Mean?

- Unenlightened English by centrelli We have all heard this phrase in some form or another but even when I, myself, tried typing this little sentence into google to see what would come up, I was surprised to see that no one could give an explanation that wasn’t lengthy or straightforward. So I’m going to try my hand at explaining this classic statement. Who said it? Rene Descartes is the man credited to these few words. The quote, originally written in french, comes from The Discourse on Method, but also appears written as the famous Latin, “Cogito ergo sum,” in his Meditations on First Philosophy, which was an attempt to find foundational truths for knowledge. The book contains six meditations that attempt to discover what is real by first doubting absolutely everything and starting from scratch. In this way, Descartes starts at the bottom and works his way up into believing in the existence of worldly things. What else do I need to know? In the First Meditations Descartes explains why he can call his beliefs into doubt, since his beliefs have deceived him before — I think we can all relate to one experience where our beliefs have been totally wrong and we feel the way old Descartes feels here.

He argues that perhaps he is currently dreaming or that God is actually a deceiving demon, or that he is simply crazy. This gives him reason to be skeptical of all his beliefs, which leads us into the Second Meditations. Here is where he convinces himself that nothing of the world is real. He essentially disbelieves everything that can possibly be called into question and whittles existence down into nothing. Then, he says as follows: I have convinced myself that there is nothing in the world — no sky, no earth, no minds, no bodies. Doesn’t it follow that I don’t exist? No, surely I must exist if it’s me who is convinced of something. But there is a deceiver, supremely powerful and cunning whose aim is to see that I am always deceived. But surely I exist, if I am deceived. Let him deceive me all he can, he will never make it the case that I am nothing while I think that I am something. Thus having fully weighed every consideration, I must finally conclude that the statement “I am, I exist” must be true whenever I state it or mentally consider it.

(Descartes, Meditation II: On the Nature of the Human Mind, Which Is Better Known Than the Body). Wait a minute, Where’s the quote!? It’s there, trust me! “I am, I exist,” is used here by Descartes to express the same thing. Meditation II is often called the cogitio for the reason that the words “I think, therefore I am,” can readily be explained with this passage. Essentialy, “I think, therefore I am” and “I am, I exist,” mean the same thing. Okay, So what does it mean? If you read the above quote from the Meditation II you see that Descartes has disproved everything that he is used to believing in. When there’s nothing left he still is left with himself and nothing else. Regardless of whether or not he is being deceived by some demon or his beliefs are wrong, he is able to see that even if he has the ability to doubt something he must be existing to even doubt it in the first place. The fact that he can think is what assures himself of his own existence, and a deceiving god cannot negate that.

From this point on, Descartes can continue in his examination of reality without worry that he is by all means existing. Conclusion “I Think, Therefore I am” is used in most intro classes to gets across the real meaning of what the cogito (Meditation II) means — A deceiver can’t deceive me of my existence, for if he were I wouldn’t exist! Although, the true quote comes from Descartes Discourse on Method, it is easier to explain it with this example. The Meditations on First Philosophy is a wonderful piece of literature that’s extremely interesting for anyone to read. If anything I said in this post sparks your interest, then I suggest you read this whole thing through yourself. That’s all for now, I hope you all now have a better understanding of what Descartes was trying to say. So, do our old pal Descartes a favor folks and keep thinking, lest you may cease to exist! I Think Therefore I Am? | On Philosophy I Think Therefore I Am? Filed under: Mind — Peter @ 12:00 am That the act of thinking guarantees the existence of the self is a fact that many philosophers take for granted.

As Descartes famously put it “I think, therefore I am”, an assertion that has come to be known as the cogito. Certainly the cogito doesn’t seem like something that can be doubted, but if we are really to rely on it we should be certain that its truth can be divorced from Descartes’ philosophy. Here then I will attempt to reconstruct the cogito, as something that cannot be doubted, using a modern philosophical approach. To defend the cogito we must first reduce it a simpler form that is easier to defend, which is an assertion that we must accept that doubts exist, since to doubt that assertion would be to prove it to be correct. However, even this form of the cogito may be attacked by a kind of radical skepticism. It is possible that what seems like a doubt to us is in actuality not a doubt, but only the appearance of one, and thus it is possible that we might consistently have something that seemed to us like a doubt about the statement “doubts exist”, since no real doubting is going on. To defeat this kind of radical skepticism we must define doubt in terms of presentations, and thus restate our initial claim as “there exist things that present themselves as doubts”.

Of course the radical skeptic may now claim that we haven’t proved that real doubts exist, only things that seem like them. This might be a real problem if we believed that a conscious act was something that existed outside of consciousness and was made available to it. This is not, however, how we approach conscious acts, conscious acts simply are their appearances. Even if the conscious act itself is part of some larger unconscious activity, what defines the conscious act as a specific conscious act is how it presents itself to us, unconscious features are irrelevant. And so our rephrasing of the initial claim isn’t even a substantive change, simply a clarification. Knowing that doubt exists we can generalize and assert that conscious acts exist, since doubts are a kind of conscious act (although we haven’t proven that anything besides doubt must exist), yielding “there exist things that present themselves as conscious acts”. From here, if we are to reach Descartes’ conclusion, we must somehow show that the self exists, and not just the conscious acts. There are basically three ways of understanding the “I” in “I think, therefore I exist”, as the real self, as the self that is constituted by the act of thinking, and as the first person perspective.

Of these three it is obvious that the existence of conscious acts can’t prove that “real self” indeed exists. What I mean by real self is the properties of the mind / conscious mind that are really had by the individual, for example certain abilities, dispositions, memories, ect. It should be obvious that a deluded individual might construe his or herself as some other individual in their thoughts, for example as Napoleon. In their thoughts they might think of themselves as having Napoleon’s memories, Napoleon’s dispositions, ect, but in reality they have none of these things, their real self is not Napoleon. Thus it is not self-contradictory to deny that the self that one thinks that they are is their real self, although it is hard to see why anyone would do this. Similar considerations reveal that it is impossible to deny that the constituted self (the self as conceived of in conscious acts) exists, since to assert “I (or this person) is not my real self” is to constitute that self in the denial. The existence of the constituted self is, however, largely irrelevant, since in conscious acts we can constitute any number of such selves, and deny that they are us.

The really interesting question, then, is if we can show that the existence of a conscious act guarantees the existence of a first person perspective, and if some constituted self must exist as a result of this. The structure of consciousness, the fact that we talk of the conscious act as a presentation, certainly implies that the act is structured around a first person perspective. For the moment then I will take it as given that without a first person perspective nothing can be conscious (since otherwise who or what would it be an appearance to?), and thus to doubt that the first person perspective exists would itself be a conscious act structured around a first person perspective, confirming its existence. Why do I say structured around a first person perspective? Simply because a radical skeptic might insist that there is no real first person perspective, only an appearance of one.* So all we can really say is that the conscious act, the experience, seems as though it has a first person perspective, but given our discussion earlier about the contents of consciousness, this is all that really matters.

And, as I alluded above, the existence of a first person viewpoint it itself a kind of minimal constituted self, since the first person perspective implies that there is someone who is having the current experience, even if it doesn’t necessarily give that self any other attributes. Despite its age the cogito is still an important part of the philosophy of mind. Unlike Descartes, we no longer take it as founding all knowledge (or as proving the existence of god). However, even apart from Descartes’ projects, the cogito is still an important argument for the existence of the mind, since the cogito, as presented above, seems to guarantee that it is impossible to consistently doubt that something like consciousness and the first person perspective exist, a point that seems to escape eliminative materialists. * In fact I agree, see here I Think, Therefore I Am I Think, Therefore I Am Written by Super User In the 17th century, the French philosopher René Descartes came up with the "explanation for it all": I think, therefore I am. This statement was the source of debates in philosophy classes. It was the existential "which came first" dilemma: the chicken or the egg?

Years later, I feel that his statement really is a fill-in-the-blanks statement. "I think _________, therefore I am _____________." n the 17th century, the French philosopher René Descartes came up with the "explanation for it all": I think, therefore I am. I remember this statement being the source of debates in philosophy classes. It was the existential "which came first" story: the chicken or the egg? Years later, I feel that his statement really is a fill-in-the-blanks statement. "I think _________, therefore I am _____________." In other words, "I think I am angry, therefore I am angry." "I think I am tired, therefore I am tired." "I think I am busy, therefore I am busy." Now before your mind starts objecting to these statements, let's take a closer look. Maybe an example from my life might help explain. This morning as I got up, I thought about all the things I have to do today, and realized it's going to be a very busy day.

So my thought was something like "I have too much to do today." I then thought about my garden and how I like to take a stroll through the garden in the morning and check out the new growth, and see who needs watering. My next thought, of course, since the previous thought had been about being too busy, was that I had no time to take a walk in the garden this morning since I had "too much to do". So let's go back to our Descartes "formula" and fill in the blanks. "I think I am too busy, therefore I am too busy." So the usual conclusion to this thought is I'm too busy to go into the garden this morning thus I don't go. [I think I am too busy to go into the garden, therefore I am too busy to go into the garden.] However, since I've been working on this programming for a while, I overrode it that limiting belief, and went into the garden anyway... and it was a lovely peaceful time for me before starting my "busy" day. Another example? OK. Someone says something to me that I consider insulting or hurtful. Let's go back to our fill in the blanks.

I think I am insulted, therefore I am insulted. Now, I do have another alternative in how I "fill in the blanks". I think I am amused, therefore I am amused. Whichever thought I choose is the one that carries over into the "I AM". If I choose to think someone has insulted me, then I am insulted. If I choose to think I am afraid, then I am afraid. If I choose to think I am impatient, then I am impatient. On the other side, if I choose to think I am at peace, then I am at peace (or at least headed in that direction). Try This Practice: Search & Replace Next time you find yourself feeling upset with someone (I think I am upset, therefore I am upset), replace that thought with, "I think I am at peace, therefore I am at peace". Of course, this is not a magic pill that instantly will change your reality (it might in some cases, but in other cases it may take a while). What it will do is change your perception of the situation. All of a sudden, it places you on the outside of your attitudes, "looking at them" rather than "being them".

You, as the observer, can stand back and see "you" the "action figure" (or the actor if you will) choosing to play the role of "I am upset", "I am angry", "I am at peace", "I am too busy", "I am hurt", etc. Once you start saying "I think I am at peace, therefore I am at peace" something shifts. It lets you see that there is another option. You are not cemented into your reactions -- they are a choice, even though we've often overlooked the fact that we had a choice. Saying I am at peace, (even if we don't feel it in the moment) helps shift our attitude from upset and anger, to a focus on choosing inner peace. Thoughts Precede Actions When you hear someone saying negative comments about you, or to you, your automatic programmed response may be "I am upset" (I think I am upset, therefore I am upset). However, in that moment, or in the moments following it, you can change that to "I think I am able to let that go, therefore I am able to let that go." First the thought, then the action. It's always been that way.

Everything starts with a thought. Even conception starts with a thought. You first think about doing something and then do it (or decide not to do it). All inventions started with a thought. Thomas Edison didn't invent the light bulb without first having a thought (or many thoughts) about it. The thoughts always precede the actions. Thus the importance of "managing" our thoughts and not let them run rampant. They are not the "directors" of our show. They are simply the precursors to action. So if you don't like the direction your life is taking, or your day, or a particular interaction, take a look at your thoughts. Maybe you're thinking "this situation stinks". Take that thought back to our "fill-in-the-blanks". I think this situation stinks, therefore this situation stinks. The problem is that once you think a situation is hopeless, then you give up on it and do nothing -- after all if it's hopeless, there is nothing you can do. Right? Wrong! It is only your belief, your thought, that says it is hopeless. There is always hope. As long as there is life, there is hope.

Even in tragic situations, while there is still life, there is still hope. Thinking Outside The Box of Our Programs We have to change our thoughts about the possibilities, about the process, about our options, about the solutions. We have to think outside the box of our habitual programmed thinking. If your thought is "this is hopeless", or there are no solutions to this, then think again. I think there is no solution, needs to be replaced with I think there is a solution. At least then we are open to there being a solution and the possibility of finding it. This also opens the door to our intuition or inner guidance to provide us with the suggestion of a solution. Anytime we are thinking ourselves into a dead-end, like I'm too busy, I have no time, I have no solution to this, etc. etc, its time to change our thinking. If I think I'm too busy, then I remain too busy to take time for anything other than the "busy-ness". If I think I have no answer to the problems that plague me, then I do not open the door for solutions to come in. A great example of this is when you say you can't remember something.

Try this next time: Instead of saying: "I can't remember" [I think I am not able to remember, therefore I am not able to remember.], say "Let me remember this" or "It's coming to me". [I think I am remembering, therefore I am remembering.] What this does is, for one, tell your subconscious mind to keep looking for that answer, and two, keeps the door open to the answer coming through. If you keep saying I can't remember, well guess what, your subconscious goes, "OK, can't remember", and it goes off to lunch and stops trying to remember. End of story. On the other hand, if you say "Let me see, what is it?" it will stay "on duty" until it finds the memory you're asking for. Leaving The Door Open For Solutions In the same way if you're searching for the solutions to a problem, if you say to yourself "I don't know what to do", [I think I am unable to find an answer, therefore I am unable to find an answer] there again you've closed the door to the answer coming through.

Saying "I am able to find the answer" opens the gate wide for the answers to come to you. We can replace those dead-end thoughts and statements with some that leave the door open for solutions. "I think I am able to discover the answer, therefore I am able to discover the answer." "I think I am capable of finding a solution, therefore I am capable of finding a solution." Now some of you might be saying this is simplistic. Well, yes it is, and that's the beauty of it. We humans seem to have a tendency to complicate things, when things really are simple. First a thought, then an action. First a belief, then a consequence of that belief. A thought, then a result to that thought (action or inaction). I think _________, therefore I am __________. Changing the Nature of our Thoughts Changes the Nature of Our Life We have disempowered ourselves by thinking "small thoughts" or dead-end thoughts thoughts fueled by low self-esteem, images of unattainable goals (to be like the "slimmer-than-life" model on TV), and thoughts rampant with self-criticism (or criticism of others).

Thoughts that are self-defeating [I think I am a failure, therefore... I think I am not smart enough, therefore... I think I am unattractive, therefore... I think I can't do this, therefore...] The belief or thought we have sets the tone for our actions, for the life we create. If there's one thing that can change our lives, it's to change the nature of our thoughts, of our beliefs. We are not powerless. We are powerful beyond measure. To quote Marianne Williamson in A Return to Love : "Our deepest fear is not that we are inadequate. Our deepest fear is that we are powerful beyond measure. It is our light, not our darkness that most frightens us. We ask ourselves, Who am I to be brilliant, gorgeous, talented, and fabulous? Actually, who are you not to be? You are a child of God. Your playing small does not serve the world. There is nothing enlightened about shrinking so that other people will not feel insecure around you. We are all meant to shine, as children do. We were born to make manifest the glory of God that is within us.

It is not just in some of us; it is in everyone and as we let our own light shine, we unconsciously give others permission to do the same. As we are liberated from our own fear, our presence automatically liberates others." "I think I am ______________, therefore I am ____________". It's up to us to fill in the blanks with the reality we desire, not the one we don't. We can change our reality. We can make a difference in our lives and in the lives of the people around us and in the world. We can be like the little engine that could: "I think I can, I think I can" therefore we can. It's really up to us! No one can change our life except us That's great because it means we don't have to wait for anyone else to change or to do anything. We have the power in our own hands to change our life, our reality, our world. "I think I can, I think I can" and then take the next step and go for it.

russell_bio cogito, ergo sum | philosophy | Britannica.com Cogito, ergo sum Alternative Titles: I think, therefore I am, Je pense, donc je suis Similar Topics Cartesian circle Cogito, ergo sum, ( Latin: “I think, therefore I am) dictum coined by the French philosopher René Descartes in his Discourse on Method (1637) as a first step in demonstrating the attainability of certain knowledge. It is the only statement to survive the test of his methodic doubt . The statement is indubitable , as Descartes argued in the second of his six Meditations on First Philosophy (1641), because even if an all-powerful demon were to try to deceive him into thinking that he exists when he does not, he would have to exist in order for the demon to deceive him. Therefore, whenever he thinks, he exists. Furthermore, as he argued in his replies to critics in the second edition (1642) of the Meditations, the statement “I am” (sum) expresses an immediate intuition , not the conclusion of a piece of reasoning (regarding the steps of which he could be deceived), and is thus indubitable.

However, in a later work, the Principles of Philosophy (1644), Descartes suggested that the cogito is indeed the conclusion of a syllogism whose premises include the propositions that he is thinking and that whatever thinks must exist. René Descartes. National Library of Medicine, Bethesda, Maryland Learn More in these related articles: René Descartes March 31, 1596 La Haye, Touraine, France February 11, 1650 Stockholm, Sweden French mathematician, scientist, and philosopher. Because he was one of the first to abandon scholastic Aristotelianism, because he formulated the first modern version of mind-body dualism, from which stems the mind-body... More about cogito, ergo sum 10 References found in Britannica Articles Assorted References Corrections? Updates? Help us improve this article! Contact our editors with your feedback. MEDIA FOR: You have successfully emailed this. Error when sending the email. Try again later. Edit Mode Submit Tips For Editing We welcome suggested improvements to any of our articles. You can make it easier for us to review and, hopefully, publish your contribution by keeping a few points in mind.

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Close Article Title: cogito, ergo sum Website Name: Encyclopædia Britannica Date Published: April 16, 2015 URL: Access Date: January 19, 2017 Share Descartes: ‘I Think Therefore I Am’ | Chapter 7: Knowledge and Learning | New Learning | New Learning Chapter 7: Knowledge and Learning Tweet Descartes: ‘I Think Therefore I Am’ René Descartes (1596–1650) was a French philosopher and mathematician, credited as a foundational thinker in the development of Western notions of reason and science. His philosophy was built on the idea of radical doubt, in which nothing that is perceived or sensed is necessarily true. The only thing that remains true that there is a mind or consciousness doing the doubting and believing its perceptions, hence the famous formulation, ‘I think therefore I am’, or in Latin, the cogito—‘Cogito ergo sum’.

Descartes also proposed that the mind and body were two separate and distinct entities, but even the body was not so certain a thing as the mind, because, like everything else in the world, the body could only be sensed because there was a mind to sense it. In 1663, Descartes’ writings were placed on a list of prohibited books by the Pope, because of the central place Descartes gave to reason and mind, rather than God, in his philosophy. Here is his explanation of the centrality of the reasoning mind in knowledge making: As I then desired to give my attention solely to the search after truth, I thought … I ought to reject as absolutely false all opinions in regard to which I could suppose the least ground for doubt, in order to ascertain whether after that there remained [anything at all] in my belief that was wholly indubitable.

Accordingly, seeing that our senses sometimes deceive us, I was willing to suppose that there existed nothing really such as they presented to us … [T]he very same thoughts (presentations) which we experience when awake may also be experienced when we are asleep, while there is at that time not one of them true, I supposed that all the objects (presentations) that had ever entered into my mind when awake, had in them no more truth than the illusions of my dreams.

But immediately upon this I observed that, whilst I thus wished to think that all was false, it was absolutely necessary that I, who thus thought, should be somewhat; and as I observed that this truth, I think, therefore I am (cogito ergo sum), was so certain and of such evidence that no ground of doubt, however extravagant, could be alleged by the sceptics capable of shaking it, I concluded that I might, without scruple, accept it as the first principle of the philosophy of which I was in search … I thence concluded that I was a substance whose whole essence or nature consists only in thinking, and which, that it may exist, has need of no place, nor is dependent on any material thing; so that ‘I’, that is to say, the mind by which I am what I am, is wholly distinct from the body, and is even more easily known than the latter … I considered myself as having a face, hands, arms, and all that system of members composed on bones and flesh as seen in a corpse which I designated by the name of body … By the body I understand all that which can be defined by a certain figure: something which can be confined in a certain place, and which can fill a

 given space in such a way that every other body will be excluded from it; which can be perceived either by touch, or by sight, or by hearing, or by taste, or by smell … [However,] I have thought I perceived many things during sleep that I recognised in my waking moments as not having been experienced at all.

What of thinking? I find here that thought is an attribute that belongs to me; it alone cannot be separated from me. I am, I exist, that is certain … I know that I exist, and I inquire what I am, I whom I know to exist … [W]hat then am I? A thing which thinks. What is a thing which thinks? It is a thing which doubts, understands, conceives, affirms, denies, wills, refuses, which also imagines and feels … For it is so evident of itself that it is I who doubts, who understands, and who desires, that there is no reason here to add anything to explain it. And I have certainly the power of imagining likewise; for although it may happen (as I formerly supposed) that none of the things which I imagine are true, nevertheless this power of imagining does not cease to be really in use, and it forms part of my thought. Finally, I am the same who feels, that is to say, who perceives certain things, as by the organs of sense, since in truth I see light, I hear noise, I feel heat.

But [sometimes it might be claimed or I might realise] that these phenomena are false and that I am dreaming. Let it be so; still it is at least quite certain that it seems to me that I see light, that I hear noise and that I feel heat. That cannot be false; properly speaking it is what is in me called feeling; and used in this precise sense that is no other thing than thinking … [P]erception is neither an act of vision, nor of touch, nor of imagination … but only an intuition of the mind, which may be imperfect and confused … or clear and distinct … according as my attention is more or less directed to the elements which are found in it, and of which it is composed … [M]y mind loves to wander, and cannot yet suffer itself to be retained within the just limits of truth … [W]hen looking from a window and saying I see men who pass in the street, I really do not see them, but infer that what I see is men … And yet what do I see from the window but hats and coats which may cover automatic machines?

Yet I judge these to be men … by the faculty of judgment which rests in my mind, I comprehend that which I believed I saw with my eyes. Descartes, Rene. 1637. Discourse on the Method of Rightly Conducting the Reason, and Seeking Truth in the Sciences. pp. 19–20. —. 1641 (1911). Meditations On First Philosophy. Cambridge: Cambridge University Press. pp. 14–17. Rene Descartes: 'I think therefore I am' Rene Descartes: 'I think therefore I am' ['I THINK, THEREFORE I AM' - DESCARTES - FROM DISCOURSE ON METHOD] I HAD long since remarked that in matters of conduct it is necessary sometimes to follow opinions known to be uncertain, as if they were not subject to doubt; but, because now I was desirous to devote myself to the search after truth, I considered that I must do just the contrary, and reject as absolutely false every-thing concerning which I could imagine the least doubt to exist.

Thus, because our senses sometimes deceive us, I would suppose that nothing is such as they make us to imagine it; and because I was as likely to err as another in reasoning, I rejected as false all the reasons which I had formerly accepted as demonstrative; and finally, considering that all the thoughts we have when awake can come to us also when we sleep without any of them being true, I resolved to feign that everything which had ever entered my mind was no more truth than the illusion of my dreams. But I observed that, while I was thus resolved to feign that everything was false, I who thought must of necessity be somewhat; and remarking this truth--I think, therefore I am--was so firm and so assured that all the most extravagant suppositions of the sceptics were unable to shake it, I judged that I could unhesitatingly accept it as the first principle of the philosophy I was seeking. I could feign that there was no world, I could not feign that I did not exist.

And I judged that I might take it as a general rule that the things which we conceive very clearly and very distinctly are all true, and that the only difficulty lies in the way of discerning which those things are that we conceive distinctly. After this, reflecting upon the fact that I doubted, and that consequently my being was not quite perfected (for I saw that to know is a greater perfection than to doubt), I bethought me to inquire whence I had learnt to think of something more perfect than myself; and it was clear to me that this must come from some nature which was in fact more perfect. For other things I could regard as dependencies of my nature if they were real, and if they were not real they might proceed from nothing--that is to say, they might exist in me by way of defect. But it could not be the same with the idea of a being more perfect than my own; for to derive it from nothing was manifestly impossible; and because it is no less repugnant that the more perfect should follow and depend upon the less perfect than that something should come forth out of nothing. I could not derive it from myself.

It remained, then, to conclude that it was put into me by a nature truly more perfect than was I and possessing in itself all the perfections of what I could form an idea--in a word, by God. To which I added that, since I knew some perfections which I did not possess, I was not the only being who existed, but that there must of necessity be some other being, more perfect, on whom I depended, and from whom I had acquired all that I possessed; for if I had existed alone and independent of all other, so that I had of myself all this little whereby I participated in the Perfect Being, I should have been able to have in myself all those other qualities which I knew myself to lack, and so to be infinite, eternal, immutable, omniscient, almighty--in fine, to possess all the perfections which I could observe in God.

PROPOSING to myself the geometer's subject matter, and then turning again to examine my idea of a Perfect Being, I found that existence was comprehended in that idea just as in the idea of a triangle is comprehended the notion that the sum of its angles is equal to two right angles; and that consequently it is as certain that God, this Perfect Being is or exists, as any geometrical demonstration could be. That there are many who persuade themselves that there is a difficulty in knowing Him is due to the scholastic maxim that there is nothing in the understanding which has not first been in the senses; where the ideas of God and the soul have never been. Than the existence of God all other things, even those which it seems to a man extravagant to doubt, such as his having a body, are less certain. Nor is there any reason sufficient to remove such doubt but such as presupposes the existence of God. From His existence it follows that our ideas or notions, being real things, and coming from God, cannot but be true in so far as they are clear and distinct.

In so far as they contain falsity, they are confused and obscure, there is in them an element of mere negation (elles participent du neant); that is to say, they are thus confused in us because we ourselves are not all perfect. And it is evident that falsity or imperfection can no more come forth from God than can perfection proceed from nothingness. But, did we not know that all which is in us of the real and the true comes from a perfect and infinite being, however clear and distinct our ideas might be, we should have no reason for assurance that they possessed the final perfection--truth. Reason instructs us that all our ideas must have some foundation of truth, for it could not be that the All-Perfect and the All-True should otherwise have put them into us; and because our reasonings are never so evident or so complete when we sleep as when we wake, although sometimes during sleep our imagination may be more vivid and positive, it also instructs us that such truth as our thoughts have will be in our waking thoughts rather than in our dreams.

[WHY I DO NOT PUBLISH 'THE WORLD'] I HAVE always remained firm in my resolve to assume no other principle than that which I have used to demonstrate the existence of God and of the soul, and to receive nothing which did not seem to me clearer and more certain than the demonstrations of the philosophers had seemed before; yet not only have I found means of satisfying myself with regard to the principal difficulties which are usually treated of in philosophy, but also I have remarked certain laws which God has so established in nature, and of which He has implanted such notions in our souls, that we cannot doubt that they are observed in all which happens in the world. The principal truths which flow from these I have tried to unfold in a treatise (On the World, or on Light), which certain considerations prevent me from publishing.

This I concluded three years ago, and had begun to revise it for the printer, when I learnt that certain persons to whom I defer had disapproved an opinion on physics published a short time before by a certain person (Galileo, condemned by the Roman Inquisition in 1633), in which opinion I had noticed nothing prejudicial to religion; and this made me fear that there might be some among my opinions in which I was mistaken. I now believe that I ought to continue to write all the things which I judge of importance, but ought in no wise to consent to their publication during my life. For my experience of the objections which might be made forbids me to hope for any profit from them. I have tried both friends and enemies, yet it has seldom happened that they have offered any objection which I had not in some measure foreseen; so that I have never, I may say, found a critic who did not seem to be either less rigorous or less fair-minded than myself.

Whereupon I gladly take this opportunity to beg those who shall come after us never to believe that the things which they are told come from me unless I have divulged them myself; and I am in nowise astonished at the extravagances attributed to those old philosophers whose writings have not come down to us. They were the greatest minds of their time, but have been ill reported. Why, I am sure that the most devoted of those who now follow Aristotle would esteem themselves happy if they had as much knowledge of nature as he had, even on the condition that they should never have more! They are like ivy, which never mounts higher than the trees which support it, and which even comes down again after it has attained their summit. So at least, it seems to me, do they who, not content with knowing all that is explained by their author, would find in him the solution also of many difficulties of which he says nothing, and of which, perhaps, he never thought.

Yet their method of philosophising is very convenient for those who have but middling minds, for the obscurity of the distinctions and principles which they employ enables them to speak of all things as boldly as if they had knowledge of them, and sustain all they have to say against the most subtle and skilful without there being any means of convincing them; wherein they seem to me like a blind man who, in order to fight on equal terms with a man who has his sight, invites him into the depths of a cavern. And I may say that it is to their interest that I should abstain from publishing the principles of the philosophy which I employ, for so simple and so evident are they that to publish them would be like opening windows into their caverns and letting in the day. But if they prefer acquaintance with a little truth, and desire to follow a plan like mine, there is no need for me to say to them any more in this discourse than I have already said.

For if they are capable of passing beyond what I have done, much rather will they be able to discover for themselves whatever I believe myself to have found out; besides which, the practice which they will acquire in seeking out easy things and thence passing to others which are more difficult, will stead them better than all my instructions. But if some of the matters spoken about at the beginning of the Dioptrics and the Meteors [published with the Discourse on Method] should at first give offence because I have called them 'suppositions,' and have shown no desire to prove them, let the reader have patience to read the whole attentively, and I have hope that he will be satisfied. The time remaining to me I have resolved to employ in trying to acquire some knowledge of nature, such that we may be able to draw from it more certain rules for medicine than those which we possess. And I hereby declare that I shall always hold myself more obliged to those by whose favour I enjoy my leisure undisturbed than I should be to any who should offer me the most esteemed employments in the world.

Question: Who said "I think, therefore I am"?
Answer: RENE DESCARTES